Rotary circuit interrupter



June 3, 1952 J. A. FAV RE 2,5995242 ROTARY CIRCUIT INTERRUPTER Filed Dec. 29, 1949 2 SHEETS-SHEET 1 Inventor":

Johh A. Favre,

-W by June 3, 1952 A, F R 2,599,242

ROTARY CIRCUIT INTERRUPTER IhventoT: John A. Pavre,

His Attorney.

Patented June 3, 1952 ROTARY CIRCUIT INTERRUPTER John A. Favre, Drexel Hill, Pa., assignor to General Electric Company, a corporation of New York Application December 29, 1949, Serial N 0. 135,796

7 Claims. 1

The invention relates to circuit interrupters and the principal object is to provide an improved rotary type of circuit interrupting mechanism having sequentially rotatable main and arcing contacts suitable for heavy-duty service within a relatively small space.

Another object is to provide an improved linear to dual rotary-motion converting mechanism having lost-motion elements for closing the rotary arcing contact of the circuit interrupter before sequentially closing the rotary main contact and opening the main contact before sequentially opening the arcing contact in interrupting the circuit.

Another object is to provide an improved main current-carrying rotary contact structure wherein two abutting main contacts are separately pivoted on spaced-apart looped conductors for wiping engagement in a restricted space between the conductors so as thereby to establish an electrodynamic wiping pressure therebetween due to the current loop reaction.

Another object is to provide an improved rotary arcing contact structure wherein a pair of axially spaced-apart and substantially radially extending stationary arcing contacts are interconnected by a bridging contact double pivotally mounted for rotation sequentially in transverse arcuate paths into engagement with the inner ends of the stationary arcing contacts in order to enabl an improved rotary type of arc quencher to be applied thereto for quenching the arcs within a relative small quadrantal space. The improved rotary arc quencher structure is more fully described and claimed in the Patent 2,568,470, granted September 18, 1951, to C. H. Titus and assigned to the assignee of the present invention.

Other objects are to provide for a substantial- 1y radially biased lost-motion takeup movement of the rotatable bridging contact relative to the two spaced-apart arcing contacts as well as a biased lost-motion takeup movement for the abutting main contacts whereby in case of erosion or burning away of the contact material during the operation of the circuit interrupter, automatic followup for both arcing and main contacts can be obtained so as to avoid failure of the interrupter due to increased tip clearance.

Further objects and advantages of the invention will appear in the following description of the accompanying drawings wherein Fig. 1 is a side view of th improved rotary type of circuit interrupter embodying the improvements of the present invention with the operating parts shown in the circuit-opening position of both the arcing and main contacts; Fig. 2 is a similar view of the circuit interrupter, with the operating parts shown in an intermediate position wherein the arcing contacts are closed but the main currentcarrying contacts are open; Fig. 3 is a similar view showing the relative positions of the operating parts when both th arcing contacts and the main contact of the circuit interrupter are closed and Fig. 4 is a cross-sectional view on the line 4--4 of Fig. 3 showing the relative positions of the arcing contacts and the relatively rotatable arc quenching members cooperating therewith.

As shown in Fig. 1, the rotary circuit interrupter embodying the improvements of the present invention is provided with a pair of oppositely rotatable main current-carrying contacts II and 12 that are respectively pivotally mounted at opposite ends thereof on the inner side of the spaced-apart current conductors l3 and I4 that are looped to form the terminals l5 and iii of the circuit interrupter. As shown, the contacts Ii and I2 ar specially formed for overlapping the other ends thereof in the space between the conductors l3 and [4. The contact II is strongly biased against the conductor I3 by the biasing springs [6a operating through the push rod IT. The contact [2 is biased to the fully open position in which it is shown by the biasing spring 20 operating on the push rod 2| and the more powerful biasing spring 22 is engaged by the outer end of the pin 21 so as to become effective just before the wiping engagement of the contact facing [2a with the contact facing Ila occurs in the space between the spaced-apart conductors l3 and li. The main contact [2 carries integral therewith a hooked arm 23 that engages with stop 24 to limit the opening movement of contact [2.

A pair of spaced-apart arcing contact members 21 shown in Fig. 1 as aligned one behind the other are connected respectively to the terminals I5 and I6 by the conductors 28 and 29 so as to be in shunt with the main current-carrying contacts I l and I2. The pair of spaced-apart arcing contacts 21 are shown embedded in an arc-quenching member 38' formed of suitable arc-resistant insulating material and having an arcuate face 3| provided with serie of alternate slots 32 and lands 33 for cooperating with the complementary slotted and landed rotatable arc-quenching member 46 to quench the arc therebetween in a relatively small quadrantal space as more fully described and claimed in the previously mentioned Titus application.

A bridging contact member 35 is double rotary mounted in accordance with the present invention for cooperating with the spaced-apart arcing contacts 27 in interrupting the circuit. As more clearly shown in Fig. 4, the bridging contact member 35 is of U-shape and is carried on a mounting member or arm 36 that is pivotally mounted on pin 31 that in turn is carried by a main mounting member or arm 38 which is pivotally mounted on the fixed pin 39 by means of yoke 46. A pin 4! is secured to the free end of arm 36 and extends through arm 38 and carries a biasing spring 42 for biasing the double pivoted mounting arms, supporting the bridging member 35, together, as shown in Fig. 1. Thus, the main pivotally mounted arm 33 carries the bridging contact 35 man arcuate path concentric with the arcuate face 3| of the arc-quenching member 30 until the bridging contact 35 is in spaced-apart alignment with the pair of arcing contacts 21. Thereupon the further rotation of arm 33 is stopped by the engagement of the end of the arm with pin 44. Hence, separate rotation of arm 36 about pin 37 against the bias of spring 42 is required to rotate the bridging contact 35 in an arcuate path transverse or intersecting the arcuate face 3| of the arc-quenching member 35 to bring the bridging contact 35 into engagement with the pair of axially spaced-apart arcing contacts 21.

The complementary semicylindrical rotatable arc-quenching member 46, formed of suitable arc-resistant insulating material, is mounted upon the main pivotal mounting member 38 and is provided with an alternate series of slots 41 and lands 43 for progressively registering with the slots and lands 32 and 33 of member 30 in quenching the arc therebetween, as more fully explained in the above-mentioned Titus application. The semicylindrical rotary arc-quench ing member 46 is further provided with a suitable recess or tunnel 49 within which the U- shaped bridging contact 35 is relatively movable, as indicated in Fig.- 4.

An improved form of linear to dual rotary motion sequential converting mechanism, indicated generally by the reference character is provided for sequentially engaging the bridging contact 35 with the spaced-apart arcing contacts 21 before effecting wiping engagement of the main current-carrying contacts H and I2 and for separating the main contacts before separating the bridging contact 35 from the arcing contact 21 in interrupting the circuit. The sequential operating mechanism 5| is provided with a pushpull operating member 52 that is guided in a substantially linear path by the grooved rollers 53 and has a link 54 pivotally connected thereto by the pin 55 for operating the roller 56 that is provided with a guide member 51 having a cam slot 58' that engageswith the pivot pin 59 on which the roller 56 is mounted so as to guide roller 56 into engagement with the pivotally mounted main contact 12 to effect wiping engagement of the contact face I2a thereof with the contact face I la of main contact H.

The push-pull operating member 52 also carries a link 60 pivotally connected thereto at one end by the pin 6| and the other end of link 60 is connected to the knee of the toggle formed by the links 62 and 63 by means of the pin 64 that forms the knee of the toggle. The toggle link 62 is connected by means of pin 66 with the pivoted arm 36 that carries the bridging contact member 35. The other toggle link 63 is provided with a pivot pin 61 that slides in an elongated pivot pin bearing slot 68 formed in the supporting side plate 63 and a biasing spring 16 is connected between the pin 67 and a stationary anchoring pin H so as to strongly bias the toggle pivot pin 6'! toward the upper end of the elongated bearing slot 63 as indicated in Fig. 1.

Operation With the circuit interrupter in the circuitopening position, as shown in Fig. l, the pushpull member 52 may be raised by any suitable closing mechanism, not shown, in order to sequentially operate the bridging contact 35 and the main contact l2 to their respective circuitclosing positions. The pivotal connecting link 60 operates on the knee pivot pin 64 to straighten up the toggle formed by the links 62 and 63, thereby rotating pivoted arm 36, the bridging contact 35, pivoted arm 38 and the semicylindrical arc-quenching member 46, all as a unit about the pivot pin 39. In this way, the bridging contact 35 is carried in an arcuate path into spacedapart alignment with the pair of spaced-apart arcing contacts 2?. Thereupon the outer end 13 of the pivoted arm 35 engages with the stop 44 to arrest further rotation of mounting member 33 about pivot pin 33. The continued straightening of the toggle formed by links 62 and 63 then serves to effect separate rotation of the mounting arm 36 about pivot pin 31 so as to carry the arcing contact 35 in an arcuate path transverse its previous arcuate path and thereby effects engagement of the ends of the U-shaped bridging contact 35 with the spaced-apart arcing contacts 2?. Further straightening and movement of the toggle formed by the links 62 and 63 overcenter produces lost motion without any further movement of the arcingcontacts 35 since the biasing spring 70 yields to permit the downward movement of the toggle pivot pin 61 in the elongated bearing slot 68 as the toggle becomes fully straightened and the knee 64 is carried overcenter. Thus, as indicated in Fig. 2, the biasing spring 15 becomes effective to operate through the toggle formed by the links 62 and 63 and exert a strong biasing force that will maintain bridging contact 35 in firm circuit-closing engagement with the spaced-apart arcing contacts 2'! even though the contact material should become eroded or burned away during operation of the interrupter. In this way an automatic wear. takeup or followup-for the bridging contact 35 is obtained.

During the double rotary operation of the bridging contact 35 in the manner just described. the link 54 is carried along by the push-pull operating member 52 and movesroller 56 under the guidance of the slot 58 to engage roller 56 with the outer side of contact [2 and thereby overcome the bias of spring 20 and move the main contact l2 adjacent to its closed position, as indicated in Fig. 2, when the bridging contact 35 has effected circuit-closing engagement with the two spaced-apart arcing contacts 21. Thereupon, further upward movement of the pushpull member 52 becomes effective to force the main contact (2 into firm wiping engagement with the main contact ll against the combined biasing forces of all the opposing biasing springs I6, 26 and 22. Atthe same time, the toggle formed by the links 62, 63 is moving overcenter so as to engage the extending end 15 of toggle link 62 against the resilient overcenter stop member 16 that is 'slidably mounted in the block 11 and biased. to the position in which it is shown in Fig. 1 by the spring I8. This enables the two interconnected operating links 54 and 60 to, in efiect, form a second toggle that is pivotally connected to the knee of the first toggle formed by the links 62 and 63 so as to exert the necessary heavy closing force through the cam-guided roller 56 required to produce full wiping engagement of the main current-carrying contacts H and 12, as shown in Fig. 3. Link 54 may be pivoted directly with contacts [2 omitting cam slot 58 if desired. The heavy end thrust exerted by this second toggle is substantially absorbed by the resiliently biased stop member 16 engaging with the end of the link 62 of the first toggle. Consequently, the resiliently biased stop member 76 serves to produce an automatic takeup or followup action in case the contact material of the main current-carrying contacts H and i2 should become eroded or burned away during the operation of the circuit interrupter since spring 78 will operate through the second toggle to compensate for such loss of contact material.

In opening the circuit interrupter, the pushpull member 52 may be moved downwardly under control of any suitable overload current-responsive tripping mechanism, not shown. Upon such opening movement of member 52, link 54 starts the reverse movement of roller 55 along with contact I2 since the hooked arm 23 is engaged with the roller pivot pin 59 so as to efiect a joint wiping movement of the main current-carrying contact faces Ila and |2a in the space between the conductors l3 and I4 under the biasing pressure of springs l6 until the movement of the contact II is stopped by the engagement of contact II with the conductor l3, as shown in Fig. 1. During such joint wiping movement of the main current-carrying contacts II and I2, the electrodynamic force produced by the current flowing in the loop including the terminals l5, l6 and conductors l3 and I4 and the two main contacts H and I2 serve to provide a strong magnetic bias that acts cumulatively with the biasing spring H; to increase the wiping pressure between the main current-carrying contact faces Na and lZa during the operation of the circuit interrupter to interrupt the circuit under overload conditions. Such cumulative magnetic and spring biasing forces serve more efiectively to prevent arcing, pitting or blow-offs during the joint wiping movement of the main contacts and until the actual separation thereof is suddenly produced by engagement of contact I l with conductor i3.

During the opening movements of the main contacts II and [2, as just described, the toggle formed by links 62 and 63 begins to move from its overcenter position in engagement with stop it, as shown in Fig. 3, through the position in which the toggle links are in alignment towards the position shown in Fig. 2. This initially increases the force exerted by the biasing spring is tending to maintain the bridging contact in firm circuit-closing engagement with the two spaced-apart arcing contacts 21, thereby insuring that the current is efiectively shunted from the main current-carrying contacts H and [2. After the separation of the main contacts I I and I2, the toggle formed by links 62 and 63 becomes quickly collapsed by the further downward movement of member 52. This enables the spring 42 to quickly move the pivoted supporting member 36 to separate the bridging contact 35 from the two spaced-apart arcing contacts 2'! and draw arcs therebetween. Thereupon, supporting member 38 is rapidly rotated about the pin 39 to rotate the bridging contact 35 along with the rotatable arc-quenching member 46 so as to draw the arcs in the narrow path between the slotted and landed nesting complementary arc-quenching members 30 and 46 and thereby rapidly cool and de-ionize the arc gases to quickly extinguish the arcs, as more fully described in the abovementioned Titus application.

What I claimas new and desire to secure by Letters Patent of the United States is:

1. A circuit interrupter having in combination, circuit-closing. means including a rotatably mounted main contact and a separate rotatably mounted arcing contact, each having a circuitclosing position,- sequential mechanism including a first-toggle for operating the arcin contact to the circuit-closing position and provided with a resilient overcenter stop and a second toggle connected between the knee of the first toggle and the main contact for sequentially operating the main contact to the circuit-closing position while the first toggle is operating overcenter against the resilient overcenter stop, and an operating member connected with the knee of the second toggle.

2. A circuit interrupter having in combination, circuit-closing means including a rotatably mounted main contact and a separate rotatably mounted arcing contact, each having a circuit closing position, and a push-pull operating member provided with linear to dual rotary-motion convertin mechanismior sequentially operating the contacts including a toggle connected to the arcing contact and a link pivotally connecting the member with the knee of the toggle for rotating the arcing contact to the circuit-closing position and a roller provided with a guide cam for engaging the main contact and a link pivotally connecting the member with the roller for sequentially rotating the main contact to the circuitclosing position while the toggle is operating overcenter.

3. A circuit interrupter having in combination, a stationary contact and a double rotary mounted cooperating contact having one mounting member pivoted for rotating the cooperating contact in an arcuate path into spaced-apart alignment with the stationary contact and a second mounting member pivoted on the one mounting member at one side of the pivot axis thereof for rotating the cooperating contact transverse said arcuate path into and out of engagement with the stationary contact.

4. A circuit interrupter having in combination, a pair of spaced-apart stationary contacts and a double rotary mounted bridging contact having one mounting member pivoted for rotating the bridging contact in an arcuate path into spacedapart alignment with the pair of stationary contacts and a second mounting member pivoted on the one mounting member remote from the pivot axis thereof for rotating the bridging contact transverse said arcuate path into and out of engagement with the pair of stationary contacts.

5. A circuit interrupter having in combination, a double rotary mounted contact provided with one mounting member pivoted for rotating the contact in an arcuate path to one position and with a second mounting member pivoted on the one mounting member for rotating the contact from the one position in a transverse arcuate path to another position, and an operating toggle having one end connected to the second mounting member and the other end provided with a, movable biased pivot pin to maintain the; contact in the other position while the toggle isv operated overcenter.

6. A circuit interrupter having in combination, an arc-quenching. member provided, with anarchate face, a pair of axially spaced-apart arcing contacts embedded in said member'with the ends of the contacts substantiallyin alignment with the arcuate face, a double rotary mounted bridge ing contact havin one mounting member pivoted for rotating the bridging contact in an arcnate path concentric with the arcuate face of the arcquenching member into spaced-apart: alignment with the pair of arcing, contacts and a. second mounting member pivoted on the one-"mounting member remote from the. axis thereof for rotating the bridging contact inanarcuate, path intersecting the arcuate; face of, the area-quenching member for engaging, the bridging contactwith the pair of arcingcontacts embedded therein, and operating means including a toggle having one end pivot-ally connected to the second mounting member and the other end provided with amovable biased pivot pin to maintain the bridging contact in engagement with the spaced-apart arcing contacts while the knee of the toggle is operated overcenter.

7. A circuit interrupter havin incomhination, engageable fixed and pivoted arcing contacts, engageable main contacts, each separately pivoted, and sequential operating mcchanismincluding. a

toggle having connections at one end with the pivoted arcing contact for rotating the pivoted arcing contact into engagement with the fixed arcing contact and provided with a biased movable mounting pivot at the other end for maintaining, engagement between the arcing contacts while the toggle is operating overcenter and a second toggle having one end connected to the knee of the first toggle and the other end provided with a cam-guided member for engaging one of the main contacts to sequentially rotate the said one main contact into wiping engagement with the other main contact while the first toggle is operating overoenter, and an operating member connected to the knee of the second togel JOHN A. FAVRE.

REFERENCES CITED The foilowing references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 974,528 cott Nov. 1, 1910 1,125,745 Scott Jan. 19, 1915 1,408,967 Arnold Mar. '7, 1922 1,935,428 Atwood NOV. 14, 1933 2,079,252 Healy May 4, 1937 2,283,748 Mathieu May 19, 1942 2,329,003 Seaman Sept. 7, 1943 

